This disclosure is based upon, and claims priority from, French Patent Application No. 98/01370, filed Jan. 22, 1998, and International Application No. PCT/FR99/00052, the contents of which are incorporated herein by reference.
The present invention relates to a standardized integrated circuit contact card, also usually referred to as a smart card.
The invention more particularly relates to a standardized smart card which can be transformed irreversibly into a standardized mini smart card.
The invention thus relates to a standardized integrated-circuit contact card of the type having a support in the form of a rectangular plate delimited by two long longitudinal edges and two short transverse edges, front and rear, which carries at least one electronic microcircuit and whose reverse face has a series of contact areas, arranged close to the front transverse edge of the card, for the electrical connection of the microcircuit to an operating circuit belonging to a device having for example a connector in which the card is fitted so that its contact areas cooperate with contact blades on the connector, and of the type having a slot with a substantially rectangular contour formed in the support, around a portion including the microcircuit and the series of contact areas, in order to delimit a detachable standardized minicard which is connected to the card support by several lugs, produced in one piece with the support, which extend between the internal edges of the cutout formed by the slot in the card and the facing edges of the minicard which are roughly parallel to the edges of the card.
According to such a known design, which is for example illustrated in the document EP-Bl-0.521.778, it is possible to simply transform the card, or a large card known as an SIM card, whose format is in accordance with the international standards GSM 11.11 and ISO 7816, into a standardized mini SIM card, whose dimensions are also defined by the international standard GSM 11.11, by detaching the latter from the card by breaking the lugs or connecting bridges, this rupture being able to be effected notably manually by pressing the minicard overall in a vertical direction perpendicular to the overall plane of the card.
This known design makes it possible to supply the card xe2x80x9ccompletexe2x80x9d to a user, that is to say of course without detaching the minicard, to enable him to use the chip with a card in one or other of the two formats (card or minicard) according to the receiving apparatus in which he has to insert the card.
The product manufactured and supplied to the users must, in addition to the standards mentioned above defining the design and geometry of the two types of card, comply with other parameters and requirements.
Each of the two cards must in particular be able to meet, in accordance with the ISO standard, mechanical strength tests including notably repeated bending/torsion cycles, without there being any visual or functional degradation of the chip, the module incorporating the chip and inserted in the card support, or the plastic body of the card forming the support proper.
These mechanical constraints must in particular be withstood by the large card, as well as of course by the minicard.
For practical reasons, it is desirable for the minicard to be able to be detached easily from the body of the large card by a manual operation, without using any specific tool and without impairing the functioning and subsequent reliability of the minicard thus obtained.
It is desirable to improve the structure of the card in order in particular to facilitate still further the manual separation, whilst guaranteeing resistance to bending/torsion in accordance with the ISO standard.
Provision is for example made for the use of more fragile chips or modules in the future and, in this case, it is preferable not to have any risks, even insignificant, of damaging the chip or module.
In addition, one or the other of the two cards must be able to be used without presenting problems of insertion or extraction of the card into or from its receiving device, and particularly in the connector, more particularly when a card is introduced into the connector in a direction substantially parallel to its overall plane with its transverse insertion edge corresponding, in the case of the large card, to its front transverse edge adjacent to the contact areas for connection of the chip and, in the case of the minicard, to one or other of its two parallel opposite transverse edges.
It is also desirable, in particular when the large-format card is used, for the cutout slot, and/or complementary grooves constituting incipient breaks in the connecting lugs, not to damage the elastic contact blades of the connector because of its repeated passage opposite the free contact ends of the contact blades of the connector during repeated operations of inserting and extracting the card.
In order to remedy the drawbacks which have just been mentioned and to satisfy the different requirements for reliability of the cards and connectors, the invention proposes a card of the type mentioned above, characterized in that each lug has two types of groove opposite each other, shaped so as to be sufficiently resistant to bending/torsion forces in accordance with a standard, one of the grooves however also being shaped so as to more easily initiate a crack by intentional manual pressure on the minicard.
According to other characteristics of the invention:
the card has three connecting lugs including a first lug extending longitudinally from the front transverse edge of the minicard adjacent to the front transverse edge of the card, whose width is at least equal to the width of the series of contact areas arranged close to the front transverse edge of the minicard, and opposing second and third lugs which each extend transversely from a longitudinal edge of the minicard,
the second and third lugs are aligned transversely and are situated close to the series of contact areas;
the second and third aligned lugs are situated approximately 17 mm from the transverse edge of the minicard from which the first lug extends;
the width of the first lug is approximately 11 mm;
the width of the second and third lugs is approximately 1.2 mm;
each of the lugs has, at least on its front face or reverse face, a groove parallel to the edge of the minicard from which the lug extends so as to constitute a portion with a reduced thickness constituting an incipient break in the lug;
the first lug has, at least on its front face or reverse face, a groove which, in cross-section, has a V-shaped profile, one leg of which, adjacent to the edge of the minicard, extends perpendicularly to the overall plane of the card;
the first lug has two identical aligned opposing grooves formed in the front face and reverse face;
each of the second and third lugs has, at least on its front face or reverse face, a groove which, in cross-section, has a V-shaped profile, one leg of which, adjacent to the edge of the minicard, extends perpendicularly to the overall plane of the card;
each of the second and third lugs has, at least on its front face or reverse face, a groove which, in cross-section, has a profile substantially in the shape of a trapezium, one edge of which, adjacent to the edge of the minicard, extends perpendicularly to the overall plane of the card and whose small base, belonging to the bottom of the groove, lies with an inclination with respect to the overall plane of the card;
each of the second and third lugs has two opposing aligned grooves, on its front face a V-shaped groove and on its reverse face a groove substantially in the shape of a trapezium.